--- /dev/null
+/*
+ * V4L2 asynchronous subdevice registration API
+ *
+ * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <media/v4l2-async.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-subdev.h>
+
+static bool match_i2c(struct device *dev, struct v4l2_async_subdev *asd)
+{
+#if IS_ENABLED(CONFIG_I2C)
+ struct i2c_client *client = i2c_verify_client(dev);
+ return client &&
+ asd->match.i2c.adapter_id == client->adapter->nr &&
+ asd->match.i2c.address == client->addr;
+#else
+ return false;
+#endif
+}
+
+static bool match_devname(struct device *dev, struct v4l2_async_subdev *asd)
+{
+ return !strcmp(asd->match.device_name.name, dev_name(dev));
+}
+
+static bool match_of(struct device *dev, struct v4l2_async_subdev *asd)
+{
+ return dev->of_node == asd->match.of.node;
+}
+
+static LIST_HEAD(subdev_list);
+static LIST_HEAD(notifier_list);
+static DEFINE_MUTEX(list_lock);
+
+static struct v4l2_async_subdev *v4l2_async_belongs(struct v4l2_async_notifier *notifier,
+ struct v4l2_subdev *sd)
+{
+ struct v4l2_async_subdev *asd;
+ bool (*match)(struct device *, struct v4l2_async_subdev *);
+
+ list_for_each_entry(asd, ¬ifier->waiting, list) {
+ /* bus_type has been verified valid before */
+ switch (asd->match_type) {
+ case V4L2_ASYNC_MATCH_CUSTOM:
+ match = asd->match.custom.match;
+ if (!match)
+ /* Match always */
+ return asd;
+ break;
+ case V4L2_ASYNC_MATCH_DEVNAME:
+ match = match_devname;
+ break;
+ case V4L2_ASYNC_MATCH_I2C:
+ match = match_i2c;
+ break;
+ case V4L2_ASYNC_MATCH_OF:
+ match = match_of;
+ break;
+ default:
+ /* Cannot happen, unless someone breaks us */
+ WARN_ON(true);
+ return NULL;
+ }
+
+ /* match cannot be NULL here */
+ if (match(sd->dev, asd))
+ return asd;
+ }
+
+ return NULL;
+}
+
+static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
+ struct v4l2_subdev *sd,
+ struct v4l2_async_subdev *asd)
+{
+ int ret;
+
+ /* Remove from the waiting list */
+ list_del(&asd->list);
+ sd->asd = asd;
+ sd->notifier = notifier;
+
+ if (notifier->bound) {
+ ret = notifier->bound(notifier, sd, asd);
+ if (ret < 0)
+ return ret;
+ }
+ /* Move from the global subdevice list to notifier's done */
+ list_move(&sd->async_list, ¬ifier->done);
+
+ ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
+ if (ret < 0) {
+ if (notifier->unbind)
+ notifier->unbind(notifier, sd, asd);
+ return ret;
+ }
+
+ if (list_empty(¬ifier->waiting) && notifier->complete)
+ return notifier->complete(notifier);
+
+ return 0;
+}
+
+static void v4l2_async_cleanup(struct v4l2_subdev *sd)
+{
+ v4l2_device_unregister_subdev(sd);
+ /* Subdevice driver will reprobe and put the subdev back onto the list */
+ list_del_init(&sd->async_list);
+ sd->asd = NULL;
+ sd->dev = NULL;
+}
+
+int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
+ struct v4l2_async_notifier *notifier)
+{
+ struct v4l2_subdev *sd, *tmp;
+ struct v4l2_async_subdev *asd;
+ int i;
+
+ if (!notifier->num_subdevs || notifier->num_subdevs > V4L2_MAX_SUBDEVS)
+ return -EINVAL;
+
+ notifier->v4l2_dev = v4l2_dev;
+ INIT_LIST_HEAD(¬ifier->waiting);
+ INIT_LIST_HEAD(¬ifier->done);
+
+ for (i = 0; i < notifier->num_subdevs; i++) {
+ asd = notifier->subdevs[i];
+
+ switch (asd->match_type) {
+ case V4L2_ASYNC_MATCH_CUSTOM:
+ case V4L2_ASYNC_MATCH_DEVNAME:
+ case V4L2_ASYNC_MATCH_I2C:
+ case V4L2_ASYNC_MATCH_OF:
+ break;
+ default:
+ dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL,
+ "Invalid match type %u on %p\n",
+ asd->match_type, asd);
+ return -EINVAL;
+ }
+ list_add_tail(&asd->list, ¬ifier->waiting);
+ }
+
+ mutex_lock(&list_lock);
+
+ /* Keep also completed notifiers on the list */
+ list_add(¬ifier->list, ¬ifier_list);
+
+ list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) {
+ int ret;
+
+ asd = v4l2_async_belongs(notifier, sd);
+ if (!asd)
+ continue;
+
+ ret = v4l2_async_test_notify(notifier, sd, asd);
+ if (ret < 0) {
+ mutex_unlock(&list_lock);
+ return ret;
+ }
+ }
+
+ mutex_unlock(&list_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL(v4l2_async_notifier_register);
+
+void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
+{
+ struct v4l2_subdev *sd, *tmp;
+ unsigned int notif_n_subdev = notifier->num_subdevs;
+ unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
+ struct device **dev;
+ int i = 0;
+
+ if (!notifier->v4l2_dev)
+ return;
+
+ dev = kmalloc(n_subdev * sizeof(*dev), GFP_KERNEL);
+ if (!dev) {
+ dev_err(notifier->v4l2_dev->dev,
+ "Failed to allocate device cache!\n");
+ }
+
+ mutex_lock(&list_lock);
+
+ list_del(¬ifier->list);
+
+ list_for_each_entry_safe(sd, tmp, ¬ifier->done, async_list) {
+ struct device *d;
+
+ d = get_device(sd->dev);
+
+ v4l2_async_cleanup(sd);
+
+ /* If we handled USB devices, we'd have to lock the parent too */
+ device_release_driver(d);
+
+ if (notifier->unbind)
+ notifier->unbind(notifier, sd, sd->asd);
+
+ /*
+ * Store device at the device cache, in order to call
+ * put_device() on the final step
+ */
+ if (dev)
+ dev[i++] = d;
+ else
+ put_device(d);
+ }
+
+ mutex_unlock(&list_lock);
+
+ /*
+ * Call device_attach() to reprobe devices
+ *
+ * NOTE: If dev allocation fails, i is 0, and the whole loop won't be
+ * executed.
+ */
+ while (i--) {
+ struct device *d = dev[i];
+
+ if (d && device_attach(d) < 0) {
+ const char *name = "(none)";
+ int lock = device_trylock(d);
+
+ if (lock && d->driver)
+ name = d->driver->name;
+ dev_err(d, "Failed to re-probe to %s\n", name);
+ if (lock)
+ device_unlock(d);
+ }
+ put_device(d);
+ }
+ kfree(dev);
+
+ notifier->v4l2_dev = NULL;
+
+ /*
+ * Don't care about the waiting list, it is initialised and populated
+ * upon notifier registration.
+ */
+}
+EXPORT_SYMBOL(v4l2_async_notifier_unregister);
+
+int v4l2_async_register_subdev(struct v4l2_subdev *sd)
+{
+ struct v4l2_async_notifier *notifier;
+
+ mutex_lock(&list_lock);
+
+ INIT_LIST_HEAD(&sd->async_list);
+
+ list_for_each_entry(notifier, ¬ifier_list, list) {
+ struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd);
+ if (asd) {
+ int ret = v4l2_async_test_notify(notifier, sd, asd);
+ mutex_unlock(&list_lock);
+ return ret;
+ }
+ }
+
+ /* None matched, wait for hot-plugging */
+ list_add(&sd->async_list, &subdev_list);
+
+ mutex_unlock(&list_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL(v4l2_async_register_subdev);
+
+void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
+{
+ struct v4l2_async_notifier *notifier = sd->notifier;
+
+ if (!sd->asd) {
+ if (!list_empty(&sd->async_list))
+ v4l2_async_cleanup(sd);
+ return;
+ }
+
+ mutex_lock(&list_lock);
+
+ list_add(&sd->asd->list, ¬ifier->waiting);
+
+ v4l2_async_cleanup(sd);
+
+ if (notifier->unbind)
+ notifier->unbind(notifier, sd, sd->asd);
+
+ mutex_unlock(&list_lock);
+}
+EXPORT_SYMBOL(v4l2_async_unregister_subdev);
Code Review / kvmfornfv.git / blobdiff